I'm not sure it makes sense to allow `node['ohai']['plugin_path']` to be an array - later in the recipe, it uses this path to create a directory, and deposit plugin files into it.  If this attribute was an array, how would you decide where to put plugins?

In any case, I don't think an intersection is what you want - you'd get false-positives if the config contains more paths than the node's `plugin_path` attribute.